Cheapest priced copy (Tempest): $0.49 at Card Kingdom, near mint, their price list as of .
Thumbscrews 
Artifact · Rare · Tempest · #312
At the beginning of your upkeep, if you have five or more cards in hand, this artifact deals 1 damage to target opponent or planeswalker.
Legal inCommanderLegacyVintage
Not legal inBrawlStandardPioneerModernPauper
1 printing · $0.49 at Card Kingdom
| Set | Number | Rarity | Card Kingdom | Foil |
|---|---|---|---|---|
| Tempest | 312 | Rare | $0.49 | — |
One ruling from Wizards of the Coast
- 4 October 2004It checks the number of cards in your hand at the beginning of upkeep, and if you have 4 or fewer cards in hand it will not trigger. It checks again when it resolves and will not deal damage unless you still have 5 or more cards in hand.