Here is how it works!

When a disc strikes the target of unarmored human tissue, it penetrates about 1" then breaks up into six (6) segments, each creating a separate wound channel, leaving a cavity of about 3 to 4 inches in diameter (about the size of a grapefruit)

The clay targets shown in these pictures are from a single disc hit.. not from the typical shell hit that would be normal in real time practices.  A total shell hit completely destroys the clay.

If you want low penetration from a magnum shell, high efficiency surface area is required.
For instance: You make a perfect dive off a diving board into the water... you keep your body straight with hands above your head to slice into the water with the least amount of resistance or impact, continuing through the water releasing the energy stored by your body.  This surface area is low efficiency.
NOW.... do the same dive ... but instead of the perfect dive, you hit the water in a belly flop.  Your body releases that energy on the surface and does not glide through the water.  This is high efficiency surface area.

SAFETYDISC®  ammunition system creates the high efficiency surface area with low penetration on impact.  100% energy release is common. With little or no penetration through the back of the clay.  Only the surface area in contact with the target RELEASE energy!  This ability allows for higher velocities resulting in a greater amount of energy to release.  There are 12 disc's per shell weighing approximately 1 3/4 oz.  with velocities of 1200fps.... doing the math, that is 2000 ft. lbs. of energy!
 

Pattern for this SAFETYDISC®  is approximately 1" per yard. Choke has little effect on pattern.  Shorter barrels will increase pattern slightly.
 

Due to its ability to release energy, risk of collateral injury or damage is at the minimum. Walls, furniture, windows, etc. All absorb the SAFETYDISC® 's energy instantly.
 

2-3/4" length 12 gage, 12 DISC, 1200 fps, 1-3/4 oz. Total DISC weight, 4 dram shell.

Packed in 5 round boxes.