Amazon has a 4-pack of 5-minute sand timers for $1.25.
Free shipping with Amazon Prime.
Choose "no rush" shipping for a $1 digital credit.
https://www.amazon.com/Teacher-Cr…B00KQ6IEC4
4 – 5 minute timers per pack.
Handy plastic timers with colored sand.
Includes suggested activities.
Each timer measures 1" x 3.5".