diff --git a/packages/api/src/routes/transceivers.ts b/packages/api/src/routes/transceivers.ts
index e17d2a7..8cff948 100644
--- a/packages/api/src/routes/transceivers.ts
+++ b/packages/api/src/routes/transceivers.ts
@@ -70,8 +70,9 @@ transceiverRouter.get("/:id", async (req: Request, res: Response) => {
       is_same_product: true,
     }));
 
-    // Market comparison: technically equivalent products from other vendors
-    // Same form_factor + speed_gbps + reach within 20% tolerance, different vendor
+    // Market comparison: strictly equivalent products from other vendors.
+    // Require hard technical evidence; unknown reach/fiber data must not act as
+    // a wildcard, otherwise breakout/AOC/cable variants leak into optic matches.
     // Only real scraped prices (url IS NOT NULL), last 30 days, max 1 per source vendor
     const comparableResult = await pool.query(
       `SELECT DISTINCT ON (po.source_vendor_id)
@@ -83,12 +84,32 @@ transceiverRouter.get("/:id", async (req: Request, res: Response) => {
          t2.fiber_type AS comp_fiber_type, t2.wavelengths AS comp_wavelengths
        FROM transceivers t1
        JOIN transceivers t2 ON (
-         t2.form_factor = t1.form_factor
+         (
+           t2.form_factor = t1.form_factor
+           OR (
+             t1.form_factor IN ('QSFP-DD', 'QSFP-DD800')
+             AND t2.form_factor IN ('QSFP-DD', 'QSFP-DD800')
+           )
+         )
          AND t2.speed_gbps = t1.speed_gbps
+         AND t1.reach_meters IS NOT NULL AND t1.reach_meters > 0
+         AND t2.reach_meters IS NOT NULL AND t2.reach_meters > 0
+         AND LEAST(t1.reach_meters, t2.reach_meters)::numeric / GREATEST(t1.reach_meters, t2.reach_meters) >= 0.85
+         AND NULLIF(t1.fiber_type, '') IS NOT NULL
+         AND NULLIF(t2.fiber_type, '') IS NOT NULL
+         AND LOWER(t2.fiber_type) = LOWER(t1.fiber_type)
+         AND substring(t1.wavelengths from '(\\d{3,4})') IS NOT NULL
+         AND substring(t2.wavelengths from '(\\d{3,4})') IS NOT NULL
+         AND ABS((substring(t1.wavelengths from '(\\d{3,4})'))::int - (substring(t2.wavelengths from '(\\d{3,4})'))::int) <= 15
          AND (
-           t1.reach_meters IS NULL OR t1.reach_meters = 0
-           OR t2.reach_meters IS NULL OR t2.reach_meters = 0
-           OR ABS(t2.reach_meters - t1.reach_meters) <= GREATEST(t1.reach_meters, 1) * 0.25
+           (
+             (t1.part_number || ' ' || COALESCE(t1.standard_name, '') || ' ' || COALESCE(t1.category, '')) !~* '(breakout|aoc|dac|twinax|active optical cable)'
+             AND (t2.part_number || ' ' || COALESCE(t2.standard_name, '') || ' ' || COALESCE(t2.category, '')) !~* '(breakout|aoc|dac|twinax|active optical cable)'
+           )
+           OR (
+             (t1.part_number || ' ' || COALESCE(t1.standard_name, '') || ' ' || COALESCE(t1.category, '')) ~* '(breakout|aoc|dac|twinax|active optical cable)'
+             AND (t2.part_number || ' ' || COALESCE(t2.standard_name, '') || ' ' || COALESCE(t2.category, '')) ~* '(breakout|aoc|dac|twinax|active optical cable)'
+           )
          )
          AND t2.id != t1.id
        )
diff --git a/sync/CURRENT.md b/sync/CURRENT.md
index 3611535..6987b98 100644
--- a/sync/CURRENT.md
+++ b/sync/CURRENT.md
@@ -1,9 +1,47 @@
 # Current TIP Sync State
 
-Updated: 2026-05-09 13:54 UTC
+Updated: 2026-05-09 14:08 UTC
 
 ## Newest Work
 
+- FS.com `QDD-2FR4-800G` false comparable correction on 2026-05-09:
+  - operator spotted that the dashboard showed invalid comparable products for FS.com `QDD-2FR4-800G`
+  - wrong examples:
+    - Flexoptix `DQ.2A858HG.z`: actually `800G QSFP-DD to 2x QSFP112 Breakout AOC`, MMF, 1-30m, not a 2km SMF FR4 transceiver
+    - NADDOD `QDD-800LPO-2DR4`: 500m, not 2km
+  - root cause:
+    - FS.com `QDD-2FR4-800G` had `reach_label=2km` but `reach_meters=0`
+    - API comparable-product SQL treated unknown reach as a wildcard, so non-1:1 products leaked into the dashboard comparison section
+  - live DB correction:
+    - `QDD-2FR4-800G`
+      - `form_factor=QSFP-DD`
+      - `speed=800G`
+      - `speed_gbps=800`
+      - `reach_label=2km`
+      - `reach_meters=2000`
+      - `fiber_type=SMF`
+      - `wavelengths=1310`
+      - `standard_name=800G QSFP-DD 2FR4`
+      - remains fully verified
+  - API correction:
+    - `packages/api/src/routes/transceivers.ts`
+      - comparable products now require hard reach evidence on both sides
+      - reach ratio must be at least `0.85`
+      - fiber type must match exactly
+      - primary wavelength must exist on both sides and be within `15nm`
+      - breakout/AOC/DAC/cable products can only compare to other breakout/AOC/DAC/cable products
+      - `QSFP-DD` and `QSFP-DD800` are treated as same form-factor family for 800G-class comparisons
+  - deployment:
+    - copied API route to Erik
+    - `pnpm -C packages/api build` passed on Erik
+    - `pm2 restart tip-api` completed, `tip-api` online
+  - health:
+    - public TIP health after restart: `healthy`, load `ok`, memory `13%`
+  - truth:
+    - `DQ.2A858HG.z` must never be shown as 1:1 comparable for `QDD-2FR4-800G`
+    - a 500m NADDOD LPO/2DR4 product must not be shown as 2km comparable
+    - unknown reach must never act as wildcard in final product comparison
+
 - FS.com 1.6T DR8/2FR4 source correction on 2026-05-09:
   - operator spotted that FS.com has two distinct 1.6T OSFP variants on the same family:
     - `OSFP-DR8-1.6T-FL`: 500m, DR8, SMF
diff --git a/sync/history/2026-05-09-fscom-qdd-2fr4-false-comparable-fix.md b/sync/history/2026-05-09-fscom-qdd-2fr4-false-comparable-fix.md
new file mode 100644
index 0000000..ebae1ee
--- /dev/null
+++ b/sync/history/2026-05-09-fscom-qdd-2fr4-false-comparable-fix.md
@@ -0,0 +1,75 @@
+# FS.com QDD-2FR4 False Comparable Fix
+
+Date: 2026-05-09
+Actor: Codex
+
+## Operator Finding
+
+The dashboard showed invalid comparable products for FS.com `QDD-2FR4-800G`:
+
+- Flexoptix `DQ.2A858HG.z`
+  - actually `800G QSFP-DD to 2x QSFP112 Breakout AOC`
+  - MMF
+  - 1-30m
+  - not a 2km SMF FR4 transceiver
+- NADDOD `QDD-800LPO-2DR4`
+  - 500m
+  - not 2km
+
+The operator was correct: these are not 1:1 equivalents.
+
+## Root Cause
+
+FS.com `QDD-2FR4-800G` had:
+
+- `reach_label=2km`
+- `reach_meters=0`
+
+The API comparable SQL treated unknown reach as a wildcard, so products with the same form factor and speed could leak into the comparison section even when reach/fiber/protocol differed.
+
+## Live DB Correction
+
+Corrected `FS.COM QDD-2FR4-800G`:
+
+- `form_factor=QSFP-DD`
+- `speed=800G`
+- `speed_gbps=800`
+- `reach_label=2km`
+- `reach_meters=2000`
+- `fiber_type=SMF`
+- `wavelengths=1310`
+- `standard_name=800G QSFP-DD 2FR4`
+- fully verified remains true
+
+## API Correction
+
+Updated `packages/api/src/routes/transceivers.ts`.
+
+Comparable products now require:
+
+- form factor exact, except `QSFP-DD` and `QSFP-DD800` are treated as one 800G family
+- same `speed_gbps`
+- known reach on both sides
+- reach ratio at least `0.85`
+- known fiber on both sides
+- same fiber type
+- primary wavelength on both sides
+- wavelength difference no more than `15nm`
+- breakout/AOC/DAC/cable products only compare to breakout/AOC/DAC/cable products
+
+This prevents unknown reach from acting as a wildcard.
+
+## Deployment
+
+On Erik:
+
+- copied API route
+- `pnpm -C packages/api build` passed
+- `pm2 restart tip-api` completed
+- public health after restart: healthy, load ok, memory about 13%
+
+## Lesson For TIPLLM
+
+Never accept dashboard/API comparable output as source truth if any core field is unknown.
+
+For final product comparisons, missing reach, fiber or wavelength evidence must exclude a candidate unless a dedicated reviewed equivalence exists. Breakout/AOC/DAC/cable products must not compare to pluggable optical transceivers unless both sides are explicitly the same breakout/cable class.